meetings - Space Flight Mechanics Committee

implemented to estimate the inertial states of both spacecraft given GPS and stereoscopic
imaging measurements aboard the primary spacecraft along with an SDRE controller to
maintain a desired trajectory about the secondary spacecraft.
16:15 AAS Alternative Hybrid Propulsion Transfers for Marco Polo NEOs Sample
13-416 Return Mission
Mauro Massari, Politecnico di Milano; Francesco Topputo, Politecnico di Milano;
Giorgio Mingotti, University of Strathclyde
In this paper the new concept of hybrid propulsion transfers is applied to the trajectory
design for the ESA MarcoPolo mission, a NEO sample return mission. The concept of
hybrid propulsion transfers combine the features of low-energy transfer, which implies
impulsive maneuver accomplished using chemical propulsion, and low-thrust transfer. The
optimization is performed with a direct transcription procedure. The problem is formulated
as a nonlinear programming problem and solved for a finite set of variables, maximizing the
final spacecraft mass. The designed hybrid propulsion transfers have been in-depth
compared with the baseline trajectories obtained for MarcoPolo mission.
16:35 AAS A simulation study of gravity and ephemeris estimation of asteroid 1999JU3
13-417 using spacecraft radiometric tracking, optical, and altimeter measurements
Hitoshi Ikeda, Japan Aerospace Exploration Agency; Yuichi Tsuda, Japan
Aerospace Exploration Agency; Yuya Mimasu, Japan Aerospace Exploration
Agency; Makoto Yoshikawa, Japan Aerospace Exploration Agency
The Japanese asteroid explorer Hayabusa-2 will be launched to return samples from
asteroid 1999JU3. The physical parameters of the target body are very important not only
for its scientific investigation but also for the spacecraft navigation. In particular, the gravity
is essential to perform a stable touch down sequence to collect samples from the asteroid’s
surface. We performed a simulation study of gravity estimation using earth-based
radiometric tracking measurements (2way RARR) and spacecraft-based measurements
(optical camera and laser altimeter) with global parameter estimation technique. We will
also present a method for ephemeris improvement of 1999JU3.
23 rd AAS / AIAA Space Flight Mechanics Meeting Page 87